Atmospheric dependency was apparently not in the original Stingray designs, judging by the RPG -- he was at least partly designing boomers to be labor on space projects. That being said, I have to agree that with biological systems they must be somewhat oxygen-dependent, which means either internal tanks, or a rebreather setup, or some combination of both.
-- Bob
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Then the horns kicked in...
...and my shoes began to squeak.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.